UNEXPECTED TITANIUM SHIFTS DURING CYCLOPROPANATION OF N,N-DIBENZYLFORMAMIDE WITH LIGAND-EXCHANGED TITANIUM-ALKADIENE COMPLEXES

A number of readily available dienes and a triene were applied to exch ange the alkene ligand on the in situ generated titanium-alkene comple xes which react with N,N-dialkylcarboxamides to give N,N-dialkylcyclop ropylamines. The ligand-exchanged intermediates were found to give the most highly substituted alkenylcyclopropylamines (abnormal products) in good yields (47-64%), rather than the least substituted alkenylcycl opropylamine (expected products). This has been attributed to an unfor eseen and unprecedented titanium migration along the ligand. (C) 1998 Elsevier Science Ltd. All rights reserved.